The invention discloses a respiratory flow adjusting device and a breathing machine. The respiratory flow adjusting device comprises a device main body, a motor and a control unit. The device main body comprises a device main body cavity, a valve core, an air inlet, an air outlet and an air flow channel communicated with the air inlet and the air outlet, wherein the valve core, the air inlet, the air outlet and the air flow channel are installed in the device main body cavity. One end of the valve core close to the air flow channel is provided with a channel plug, gaps between the channel plug and the air flow channel are different when the channel plug is located at the different positions in the air flow channel, air flows passing through the air flow channel are stored in the control unit and corresponds to an rotary angle of a motor shaft of the motor, and the control unit drives and controls the valve core through the rotary angle of the motor shaft and further enables the channel plug to be stayed at the corresponding position in the air flow channel. The automatic and accurate control of the air flows can be achieved, and simultaneously the damage of a rotational potentiometer due to excessive rotation of the motor shaft is effectively avoided.
